1. Field of the Invention
The present invention relates to game equipment which employs a picture display screen, and on which various games such as a role-playing game and a puzzle game can be played.
2. Description of the Related Art
A common type of a conventional game equipment employing a picture display screen allows a game to be played thereon when a board in which a game program has been stored, is inserted into a receptacle of the game machine of the game equipment. The board has a read-only memory (hereinafter referred to as a "ROM") storing the game program. After the board is connected with the game machine, the game proceeds with pictures for the game being displayed on the display screen of a picture display such as a liquid crystal display (hereinafter referred to as an "LCD") provided on the game machine or a television receiver (hereinafter referred to as a "CRT") connected with the game machine, while the player operates on operation buttons, etc. of the game machine.
The game machine has a microprocessor (hereinafter referred to as a "CPU") for controlling selections made in the game and the proceeding of the game, etc., a power supply, and a random-access memory (hereinafter referred to as a "RAM") having a certain fixed capacity. The proceeding of the game is controlled by reading a game program from the ROM of the board, and using a plurality of registers of the RAM incorporated in the game machine. Those registers whose addresses have been specified are used to arrange/rearrange and store information, on the basis of which a title picture and various images for the game are displayed on the picture display such as the LCD or CRT. The other registers are used to cause movement of characters of the game, to read commands, and for other purposes.
Since, in recent years, games which can be played on such game equipment have become complicated, some of the game equipment have been provided with the following arrangement. A RAM and a backup power supply are incorporated in the board so that a selection of a save command during the proceeding of a game may cause the current situation of the game to be stored in the RAM in the board. With this arrangement, even if the power supply for driving the game machine is turned off, the player is able to select how he starts playing the game next time (i.e., starts the next game activity), whether the game is to be restarted or it is to be continued from the situation in which the previous game activity has ended.
Thus, it is possible nowadays to use a board which has a RAM and a backup battery, and which is adapted to store the current situation of the game proceeding in response to a save command. However, there is an inconvenience. Only limited opportunities arise to permit a save command to be input. If a save command has not been input, the game cannot be interrupted but it has to be continued until a subsequent save command will be input. This is inconvenient when the player desires to have a break or has something else to do. In addition, when the game has been hurriedly interrupted by the player because of his urgent business or when the drive power supply of the game machine is almost exhausted, the equipment fails to positively save the game.
Some of the many complicated games (such as role playing games and puzzle games) which have been recently offered, require ten and several hours to several tens of hours to complete one game. If such a game is played on a game machine driven by a battery, there are the following drawbacks and disadvantages. Since, in general, the battery becomes exhausted after a game activity has been continued for several consecutive hours, the battery has to be replaced before one game is completed. Further, since the game must be continued until a save command is input during the proceeding of the game, in the event that the battery has become exhausted in the course of the game, all information occurring after the exhaustion is lost. If, in order to avoid this disadvantage, the battery is replaced earlier than necessary, some of the power is inevitably wasted. The above drawback and disadvantage could be avoided by adopting an arrangement for allowing the current situation represented on the screen to be immediately saved. However, such an arrangement has not been realized.
Even if it is made possible, for example, by some improvement of the battery, to continuously play the game for a long time, there would be another disadvantage. Although the game equipment can be continuously powered even when the player has to interrupt the game because of an emergency, this means the battery is used in vain.
In the case where a domestic power source is used, there is the following disadvantage. When the power source supplying power to the game machine is accidentally disconnected by, for instance, a person tripping over the power cord, at least part of the information on the game proceeding is lost, and the player may have to restart the game.